(a) The ambient air quality standards for the territory of American Samoa shall be the same as the National Primary and Secondary Air Quality Standards set forth at 40 CFR 50.1, et seq. These standards are enumerated below:

(1) The American Samoa ambient air quality standard for sulfur oxide measured as sulfur dioxide is 1,300 micrograms per cubic meter (0.5 p.p.m.) maximum 3-hour concentration not to be exceeded more than once per year; the 24-hour standard is 0.14 p.p.m not to be exceeded more than once per year; and the annual standard is 0.030 p.p.m not to be exceeded in a calendar year.

(3) The American Samoa ambient air quality standard for ozone (measured by reference to 40 CFR 50 appendix D) is .12 parts per million (235 mg/m3).

(4) The American Samoa ambient air quality standard for nitrogen dioxide is 0.053 parts per million (100 micrograms per cubic meter) annual arithmetic mean concentration.

(5) The American Samoa ambient air quality standard for lead is 1.5 micrograms per cubic meter maximum arithmetic mean over a calendar quarter.

(6) The American Samoa ambient air quality standard for carbon monoxide is 10 mg/m3 (9ppm) as a maximum 8-hour average concentration not to be exceeded more than once per year, and 40 mg/m3 (35 ppm) maximum 1-hour average concentration not to be exceeded more than once per year.

(b) Measurements for American Samoa ambient air quality standards shall be determined using methods set out in 40 CFR part 50, including appropriate appendices thereto, or by any other methods approved in advance by the Commission.

(c) These numerical air quality standards are the maximum allowable concentrations of pollutants in the ambient air necessary to protect the health and welfare of the people of American Samoa. No degradation of the quality of the ambient air shall be permitted in areas in which the concentrations of the identified pollutants are lower than the numerical standards established by these Standards and Regulations unless such lowering of air quality will not violate any applicable federal law or regulations (including prevention of significant deterioration) and it has been adequately demonstrated to the executive secretary that a degradation of the air quality in an area is justified as a result of necessary economic or social development and that such lowering of air quality will not seriously interfere with or become injurious to the health, enjoyment, and comfortable enjoyment of life or property.